refactor(web): centralize multi-select release handling

apps/web/src/hooks/useTimelineDrag.ts

@@ -23,8 +23,8 @@ import { createAllocationDragState } from "./timelineAllocationDragState.js";
 import { attachDocumentMouseDrag } from "./timelineDocumentDrag.js";
 import { buildProjectShiftMutationInput, createProjectDragState } from "./timelineProjectDrag.js";
 import {
+  completeMultiSelectDraft,
   createMultiSelectState,
-  finalizeMultiSelectDraft,
   updateMultiSelectDraft,
 } from "./timelineMultiSelect.js";
 import { reconcileOptimisticEntries } from "./timelineOptimisticAllocations.js";
@@ -896,21 +896,9 @@ export function useTimelineDrag({
       const ms = multiSelectRef.current;
       if (!ms.isSelecting) return;
 
-      const finished = finalizeMultiSelectDraft(ms, ev.clientX, ev.clientY);
-      if (!finished) {
-        // Minimal movement → not a drag selection, reset.
-        // Let existing onContextMenu handlers on allocation blocks handle right-click.
-        multiSelectRef.current = INITIAL_MULTI_SELECT;
-        setMultiSelectState(INITIAL_MULTI_SELECT);
-        return;
-      }
-
-      // Keep the rectangle coordinates for the parent to compute intersection.
-      // isSelecting is set to false to indicate the drag is done, but the
-      // rectangle data (startX/Y, currentX/Y) is preserved so TimelineView
-      // can resolve which allocations/resources fall within the selection.
-      multiSelectRef.current = finished;
-      setMultiSelectState(finished);
+      const result = completeMultiSelectDraft(ms, ev.clientX, ev.clientY, INITIAL_MULTI_SELECT);
+      multiSelectRef.current = result.nextState;
+      setMultiSelectState(result.nextState);
     }
 
     multiSelectCleanupRef.current = attachDocumentMouseDrag(document, handleMove, handleUp);